The two models represent the magazine’s focus this year to celebrate body diversity and age inclusion. Even though Upton already has two covers under her belt (well, under her chain-link jewelry “bikini”) she was excited to return because of the issue’s very focused mission. “For SI to emphasize every different type of perfect is really inspiring,” Upton tells Sports Illustrated. “Those are the campaigns I want to do and the career I want to have — to inspire women to love themselves.”

Brinkley thought her bikini days were over once she turned 30, but now is hoping to influence a change in the stigma around aging. “In a country that’s very ageist, people love to put you in little boxes,” she says. “Women feel very limited by their numbers. On a personal level, I thought, if I can pull this off, I think it will help redefine those numbers and remove some of the fear of aging.”

She’s been celebrating all week with plenty of throwback pics and behind-the-scenes snaps from set, including this pic of her striking a pose behind a straw hat, masterfully captioning her pic, “The photos of my babies make this mama bristle with pride.”